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Calculations of sophisticated impact scenarios (especially three-dimensional ones) are leading to a huge amount of data. Thus, visualization is not only a useful working step for presenting results. It has now become to a central topic in impact research.

We developed VIMoD (=Visualization of Impact MOdelling Data), a powerful software which enables a three-dimensional visualization and analysation of modelling data derived from both iSALE and iSALE-3D. VIMoD is completely written in C++. It comes with a Qt-based, user friendly GUI and uses OpenGL to generate the graphics output. The rendered data can be easily rotated or moved. Thus, arbitrary views of the data are possible. VIMoD contains a broad variety of visualization methods (isosurfaces, cutfaces, vectors, tracer and trajectory representations, ...). It enables high-resolution snapshot generation as well as encoding of videos in different formats and qualities. It comes with a plugin-interface which allows to write your own add-ons and thus eases the post-processing of the data.

While installing vimod on your machine, a configuration file is created:

${HOME}/.vimod2/default.conf

In this file some default visualization settings, appearance and behavior of VIMoD is stored. You can change these settings according to your own wishes.NOTE: It is highly recommended to create a backup of your configuration file before performing any changes - in particular, if you are not familiar with VIMoD.

Explaining all the different visualization techniques, their functionality, different options and the theory behind is currently beyond the scope of this wiki. Most of the primary visualization techniques (arranged in a tab in the control panel of vimod) are activated as follows:

select the desired visualization method by clicking the appropriate tab in the control panel (left side of the vimod window).

select the field which you like to visualize from the field list (located above the tab folder)

Press the key 'F2' (or select 'Media' --> 'snapshot' from the menu) to create a snapshot of the current visualization. The output is stored in the current working directory as an image file (usually JPEG, you can change the output format by choosing 'Options'->'Preferences'->'Media options').

To allow vimod create videos of your visualizations the 'mencoder' package must be installed on your computer and 'mencoder' must be found in your PATH-environmental settings2. To render a video perform the following steps

adjust the visualization according to your own wishes.

jump to the timestep with which the video should start with.

select the appropriate timestep skip value (note that a video usually requires 25 timesteps per second).

The video is found in the location you specified in the configuration dialog (see above) or adjusted in your local configuration file in a subfolder called newmovie/newmovieXXX (where XXX is a three-digit consecutive number). The video usually is called msmpeg4.avi. All the frames of the movie are additionally stored in the subfolder 'img'.

1 Note that the existence, meaning and behavior of the flags might change from time to time. Call 'vimod --help' for an up-to-date list of all available flags.

2 Just type in 'mencoder' from the command line if you are not sure whether all your requirements are satisfied - if you get no error, everything is fine.